T-60 Docked changes desktop on power failure

[rebop]

This is curious to me. If my Thinkpad is docked and I have a power failure (like last night) it switches to battery but alos switches the desktop layout as if the screen has changed from the external monitor to the internal panel.

I could see if the lid was opened having this change, but not just switching power source.

Is there a way I can prevent this unless I am undocked or open the lid?

Thanks.

~Bob